Lid for pressure resisting vessels



y 1 8- s. HALL 1 2,116,170

LID FOR PRESSURE RESISTING VESSELS Filed July 17, 1936 CcilSHall,

33,4, KP. W80;

Patented May 3, 1938 PATENT oFFrcE Y 1 LID FOR, reassess assrs'rmo VESSELS Cecil Stuart Hall, London, England, assignor to Refrigeration Patents Limited, a corporation of Great Britain Application July 17, 1936, Serial No. 91,209 In Great Britain July 30, 1935 4 Claims.

. This invention relates to lids for pressure resisting vessels in which fluids are stored or generated under pressure and in particular to lids for pressure resisting vessels of the type in which 5, the sealing of the lid is assisted by the pressure within the vessel, such as that described in U. S. Patent No. 1,932,135. These lids are intended forms with pressure resisting vessels adapted for the liquefaction or gasification of solid carbon 10 dioxide.

In the said patent a construction is described in which a vessel is sealed by means of a lid and a soft gasket arranged in contact with the outer rim of the lid, with the wall of the pressure resistingivessel andwith a following ring of metal. This latter is adapted to be locked in position and in the mouth of the pressure resisting vessel by partial rotation, so that segmental projec tions on the outer circumferential surface of the ring bear against corresponding projections in the mouth of the vessel, thus preventing outward movement of the ring. The rim of the lid is then brought tightly to bear on the gasket by means of a stud, which is secured to the centre of the lid, the said stud carrying at its outer end a nut or handle which can be screwed down on an intermediate cross piece or other supporting member which is incapable of substantial inward movement. 30 In sealing devices of the type described, if the following ring is rotated to the unlocked position While there is any considerable pressure existing in the vessel, there is the risk that, instead of the sealing joint being broken to allow of escape 35 of gas, the entire sealing device, comprising lid, gasket and following ring, may be ejected forcibly from the mouth of the vessel. Furthermore, in the operationof making the sealing joint after the vessel has, for example, been charged with 40 solid carbon dioxide, any rapid gas evolution may cause the lid to rise into sealing engagement with the gasket before the following ring has been locked into position and some difficulty may be experienced in inserting the sealing device into the correct locking position.

In U. S. Patent No. 1,966,851 a sealing device is described in which means are provided for raising and lowering the lid in relation to the mouth of the vessel and the following ring, and also means are provided for simultaneously preventing rotation of the following ring except when the lid is lowered and is out of sealing contact with the following ring and gasket.

55 The present invention represents an improvement in or modification of the sealing device referred to in the preceding paragraph.

According to the present invention, means are provided for preventing rotation of the lid relative to the mouth of the vessel, and the lid or a member fixed thereto has one or more projections adapted to engage in a corresponding number of recesses formed in the following ring, or in a member attached thereto, and of just sufficient width to accommodate the projection or 10 projections, the arrangement being such that when the projection and recess do not register, the projection rides on the underside of the fol,- lowing ring or on a ledge attached theretoor on the underside of the member attached to the fol- 15 lowing ring, and thereby keeps the lid out of contact with the gasket. The prevention of rotation of the lid relative to the mouth of the vessel may be efiected by rigidly attaching one or more projections to the lid or to the stud which is fixed to the centre of the lid, each of these projections fitting into a recess in the mouth of the vessel which permits only of a vertical movement of the lid without any rotation. For this purpose it is convenient to utilize the recesses which exist between the segmental projections in the mouth of the vessel for holding the following ring in place against outward movement.

The accompanying drawing shows isometric sectional views of the device applied to a pressure vessel. Figure 1 shows the device in the position when the vessel is sealed, and Figure 2 shows the position of the parts when the sealing device is in the mouth of the vessel, but gas is allowed to escape past the lid. 5

The lid 2 is provided with a stop H on its upper side and this fits into a recess in a projection I2 on the following ring 3 when the latter is locked in the mouth of the vessel. The lid 2 has also a lip ll located in the'recess lfl between 40 projections B so as to prevent rotation.

In order to remove the sealing device from the mouth of the vessel, the handle 1 bearing against the rigid crossbar 6 is rotated in an anti-clockwise direction so that the lid 2 is lowered by means of the member 5, so that the projection I3 slides downwardly out of the recess in the projection l2 on the following ring 3. Thelid 2 is now out of contact with the gasket 4 and gas may escape from the vessel and any pressure above atmospheric is relieved. The ring 3 is now partly rotated in a counter-clockwise direction by means of the handle 8 until the projections M are no longer under the corresponding projection 9 in the mouth of the vessel. The members are now in the position shown in Figure 2, and the whole sealing device may be lifted out of the vessel.

The placing of the sealing device into position and the completing of the sealing of the vessel by bringing the lid 2 into contact with the gasket 4 is precisely the reverse operation of the method of removal above described. The total extent of the downward movement of the stud 5 is such that the projection I3 is just able to emerge from the recess l3a, and the rotational movement of the following ring 3 is limited by the projection I3 engaging stops l2a at the extremities of the ledge 12, thus permitting just the right amount of rotation to bring the projections 14 and 9 into register.

I claim:

1. A sealing device for a pressure vessel having a cylindrical opening with an inner circumferential recess near its outer end and longitudinal recesses extending from its mouth to the said circumferential recess; a removable ring of eX- ternal diameter equal to the diameter of the opening and provided with projections corresponding to the said longitudinal recesses so that by partial rotation of the ring Within the opening, the said projections enter the circumferential recess and lock the ring against outward movement; a lid and a gasket adapted to form a fluid-tight seal with the mouth of the vessel and with the side of the ring furthest within the vessel; means for preventing relative rotation between the lid and the mouth of the vessel; at least one projection or recess on the lid and at least one recess or projection on the ring adapted to engage with each other, their relative size and positions being chosen so that their engagement is only possible when the ring is in the locked position and prevents relative rotation between the ring and the lid and their non-engagement prevents fluid-tight contact between the lid and the gasket; and means for drawing the lid towards the ring so as to compress the gasket into fluid-tight contact with the wall of the vessel and with the ring and the lid.

2. A sealing device as set forth in; claim 1, in which the means for preventing rotation of the lid relative to the mouth of the vessel comprise at least one projection rigidly attached to the lid, and registering in a recess formed in the mouth of the vessel, said recess permitting only of vertical movement of the lid without any rotation.

3. A sealing device as set forth in claim 1, in which the means for preventing rotation of the lid relative to the mouth of the vessel comprise at least one projection rigidly attached to the lid which engages a longitudinal recess in the mouth of the vessel serving for the introduction and locking of the ring.

4. A sealing device as set forth in claim 1, in which the means for drawing the lid towards the ring comprise a vertical threaded stud attached to the lid, a cross piece adapted to engage the upper portion of the mouth of the vessel, means engaging the stud and the cross piece and adapted upon being rotated to draw the lid towards the ring.

CECIL STUART HALL. 

